num = 9
if 0 <= num <= 10:  # 判断值是否在0~10之间
    print('hello')
# 输出结果: hello

num = 10
if num < 0 or num > 10:  # 判断值是否在小于0或大于10
    print('hello')
else:
    print('undefine')
# 输出结果: undefine

num = 8
# 判断值是否在0~5或者10~15之间
if (0 <= num <= 5) or (10 <= num <= 15):
    print('hello')
else:
    print('undefine')
# 输出结果: undefine

var = 100

if var == 100: print("变量 var 的值为100")

print("Good bye!")
